The present invention relates to anchors such as those found on small boats and yachts. More particularly, the present invention relates to a collapsible anchor having a plurality of flukes which are normally radially extended from the lower portion of an anchor shank but may be collapsed so as to extend axially from the anchor shank.
Collapsible anchors having a plurality of normally radially extending flukes are well-known in the art. Such anchors have the advantage that the flukes readily engage the bottom surface of a body of water or engage objects such as rocks, logs, and the like on the bottom to retain the anchor and thereby hold a boat to which the anchor is connected by an anchor line. However, the extended flukes create some difficulties for the boatman in that the flukes frequently engage some object on the water's bottom in such a manner that the anchor cannot be raised when the boatman is ready to do so. To overcome this difficulty, the prior art teaches various mechanisms for collapsing the flukes so that the anchor may be more readily dislodged from an entrapped position.
Generally speaking, the prior art has taken two approaches. In the first approach, as exemplified by U.S. Pat. Nos. 3,747,553 and 4,005,671, a release means is provided which automatically releases the flukes upon application of a predetermined tension to the anchor line. This approach has a disadvantage in that the tension in the anchor line may be sufficient to release the flukes even though the anchor is not entrapped. In the second approach, as exemplified by U.S. Pat. Nos. 3,082,729 and 3,283,736, a line separate from the anchor line is provided. When it is determined that the anchor is entrapped, the boatman pulls this second line to operate the release mechanism which collapses the flukes. This approach has a disadvantage of requiring a separate line which frequently becomes entangled with or wrapped around the anchor line as the anchor rotates in its descent to the bottom.